The invention of this application relates to rotary couplings or couplers and more particularly to a rotary coupler configured to use in connection with a tooling fixture. While it has been found that the rotary coupler of this application works particularly well in connection with fixtures and fixturing and thus will be described with reference thereto, the rotary coupler of this application has broader applications wherein this application should not be limited to fixturing arrangements.
Rotary couplers are known in the field and are utilized to direct some form of flow, such as electrical or fluid flow, between a stationary source and a rotating object. As referenced above, this application is directed to a fluid flow between a pressurized fluid source and a rotating fixture which utilizes this pressurized fluid to clamp a workpiece to the fixturing. This can be utilized for a wide range of manufacturing operations including, but not limited to, fixtures configured to hold a workpiece, or a plurality of workpieces, for a machining operation such as a computer controlled machining operation (CNC). The fixture utilized in CNC machining can be a multi-sided fixture having, for example, four sides and each of these sides having a clamping device configured to clamp one or more workpieces to the fixture. Each of these sides can also include a separate valve for controlling the clamping of the fixture on the particular side.
In operation, the operator of the machining center would load one or more parts into one side of the fixture at a time. Once the parts are loaded in this first side, a valve would be opened to allow the pressurized fluid to enter that side of the fixture and to actuate the clamps to lock the workpieces in place. The operator would then rotate the fixture 90°, for a four sided fixture, to align themselves with the second side of the fixture. Once in place, the operator can load workpieces in the fixture in the second side. This process continues until all sides of the fixture have been loaded. Once all sides are loaded, the fixture can be moved into a machining position wherein the four sides of the fixture can be machined.
In one particular machining operation, the CNC machine can have two stations wherein one station is a load station and the other station is a machining station. These two stations can be separated by a barrier wall to protect the operator who is loading the fixture in the loading station from the machining operation at the other station. Once the fixturing is moved into the loading station, the operator attaches fluid lines to the fixturing to allow the actuation of the clamps or holding devices on the four sides of the fixturing. Once the lines are connected, the operator can actuate the clamps and unload the machined workpieces from each side and replace them with raw workpieces for machining. Once all four sides are unloaded and then re-loaded, the operator removes the hydraulic lines and the fixturing is ready for machining. As can be appreciated, the constant removing and connecting of the fluid lines makes it such that quick connects are utilized to connect these fluid lines to the fixturing.
In prior art workholding devices, the operator must actuate a manual shut-off valve in the pressurized fluid line between an opened and a closed position before the hydraulic lines could be removed. Similarly, when the fixture is moved to the loading station, the operator first connects the fluid lines to the fixture and then must open this main valve to allow the actuation of each individual fixtures. At that time, the operator proceeds as is described above. Then, once the fixtures are loaded, the operator again turns off the main valve and then removes the fluid lines from the fixture.
With reference to FIGS. 1 and 2, a prior art fixturing arrangement is shown. FIG. 1 shows a prior art coupling device CD joined to a four-sided fixture F. Fixture F includes a top plate TP which is a horizontally positioned top plate. Coupling device CD includes a rotary coupler RC having a hub H and a base B. Pressure line PL and tank line TL are permanently fixed to the ports P in hub H. Base portion B of the rotary coupler includes a tank line outlet TLO for tank feed line TFL which is permanently joined to base B and which includes a quick connect coupling device QCT on its opposite end to selectively connect tank feed line TFL to a tank line connector TLC which is mounted to top plate TP. The flow of pressurized fluid from pressure line PL is also selectively connectable by way of quick connect QCP. QCP includes a quick connect QC1 joined to base B which can be selectively connected with a quick connect QC2 wherein quick connect QC2 is permanently joined to a main valve MV on the top side of the main valve. The bottom side of the main valve is joined to top plate TP providing the fluid with connection of the pressure line to fixture F. Once the component parts are loaded onto all four sides of fixture F, the quick connect for both of the tank line and pressure line QCT are removed and the fixture can then be indexed into the machining position of the machining center which is best shown in FIG. 2.
As can be seen in these figures, the coupling device CD has a height HT that extends a significant distance above top plate TP of the fixturing which can make use of this coupling device very difficult. Further, in some applications, this coupler arrangement cannot be used in that it will not fit within the enclosure of the machining center. This particular coupling device arrangement is approximately 1.5 feet tall. In this respect, rotary coupler RC is over 7″ long and it makes up only a fraction of the overall height of coupling device CD.
In operation, once fixture F reaches the loading station, quick connect QC1 must be connected to quick connect QC2 to provide the fluid connection for the pressure line in this system. Then, tank feed line TFL must be joined to tank line connector TLC. Once these two connections are made, valve handle VH of main valve MV is turned to an opened position to allow the pressurized fluid to flow into fixture F. At this time, the operator can unload and load new workpieces on each side of fixture F. Once each side of the fixture is loaded, the operator must then close main valve MV by actuating valve VH. Then, the operator would remove the connection of the tank line and the connection for the pressure line thereby removing the top portion of the coupling device which must then be moved out of the way while the operator closes the machining door and indexes the system. As can be appreciated, this large object that the operator must handle is clumsy and the several connections and manual valve operations are time consuming. As a result, while the coupling device CD can be used to effectively clamp workpieces, it is inefficient and cannot be used for all machining operations.